TY - JOUR A1 - Rosenblum, Michael A1 - Pikovskij, Arkadij A1 - Kurths, Jürgen T1 - Phase synchronization in driven and coupled chaotic oscillators Y1 - 1997 ER - TY - JOUR A1 - Rosenblum, Michael A1 - Pikovskij, Arkadij A1 - Kurths, Jürgen T1 - Effect of phase synchronization in driven chaotic oscillators Y1 - 1997 ER - TY - JOUR A1 - Pikovskij, Arkadij A1 - Kurths, Jürgen T1 - Coherence resonance in a noise-driven excitable system Y1 - 1997 ER - TY - JOUR A1 - Romano, Maria Carmen A1 - Thiel, M. A1 - Kurths, Jürgen A1 - Kiss, Istvan Z. A1 - Hudson, J. L. T1 - Detection of synchronization for non-phase-coherent and non-stationary data N2 - We present a new method to detect phase as well as generalized synchronization in a wide class of complex systems. It is based on the recurrences of the system's trajectory to the neighborhood of a former state in phase space. We illustrate the applicability of the algorithm for the paradigmatic chaotic Rossler system in the funnel regime and for noisy data, where other methods to detect phase synchronization fail. Furthermore, we demonstrate for electrochemical experiments that the method can easily detect phase and generalized synchronization in non-phase- coherent and even non-stationary time series Y1 - 2005 SN - 0295-5075 ER - TY - JOUR A1 - Zhou, Changsong A1 - Kurths, Jürgen A1 - Kiss, Istvan Z. A1 - Hudson, J. L. T1 - Noise-enhanced phase synchronization of chaotic oscillators Y1 - 2002 ER - TY - JOUR A1 - Stolbova, Veronika A1 - Surovyatkina, Elena A1 - Bookhagen, Bodo A1 - Kurths, Jürgen T1 - Tipping elements of the Indian monsoon: Prediction of onset and withdrawal JF - Geophysical research letters N2 - Forecasting the onset and withdrawal of the Indian summer monsoon is crucial for the life and prosperity of more than one billion inhabitants of the Indian subcontinent. However, accurate prediction of monsoon timing remains a challenge, despite numerous efforts. Here we present a method for prediction of monsoon timing based on a critical transition precursor. We identify geographic regions-tipping elements of the monsoon-and use them as observation locations for predicting onset and withdrawal dates. Unlike most predictability methods, our approach does not rely on precipitation analysis but on air temperature and relative humidity, which are well represented both in models and observations. The proposed method allows to predict onset 2 weeks earlier and withdrawal dates 1.5 months earlier than existing methods. In addition, it enables to correctly forecast monsoon duration for some anomalous years, often associated with El Nino-Southern Oscillation. Y1 - 2016 U6 - https://doi.org/10.1002/2016GL068392 SN - 0094-8276 SN - 1944-8007 VL - 43 SP - 3982 EP - 3990 PB - American Geophysical Union CY - Washington ER - TY - JOUR A1 - Boers, Niklas A1 - Goswami, Bedartha A1 - Rheinwalt, Aljoscha A1 - Bookhagen, Bodo A1 - Hoskins, Brian A1 - Kurths, Jürgen T1 - Complex networks reveal global pattern of extreme-rainfall teleconnections JF - Nature : the international weekly journal of science N2 - Climatic observables are often correlated across long spatial distances, and extreme events, such as heatwaves or floods, are typically assumed to be related to such teleconnections(1,2). Revealing atmospheric teleconnection patterns and understanding their underlying mechanisms is of great importance for weather forecasting in general and extreme-event prediction in particular(3,4), especially considering that the characteristics of extreme events have been suggested to change under ongoing anthropogenic climate change(5-8). Here we reveal the global coupling pattern of extreme-rainfall events by applying complex-network methodology to high-resolution satellite data and introducing a technique that corrects for multiple-comparison bias in functional networks. We find that the distance distribution of significant connections (P < 0.005) around the globe decays according to a power law up to distances of about 2,500 kilometres. For longer distances, the probability of significant connections is much higher than expected from the scaling of the power law. We attribute the shorter, power-law-distributed connections to regional weather systems. The longer, super-power-law-distributed connections form a global rainfall teleconnection pattern that is probably controlled by upper-level Rossby waves. We show that extreme-rainfall events in the monsoon systems of south-central Asia, east Asia and Africa are significantly synchronized. Moreover, we uncover concise links between south-central Asia and the European and North American extratropics, as well as the Southern Hemisphere extratropics. Analysis of the atmospheric conditions that lead to these teleconnections confirms Rossby waves as the physical mechanism underlying these global teleconnection patterns and emphasizes their crucial role in dynamical tropical-extratropical couplings. Our results provide insights into the function of Rossby waves in creating stable, global-scale dependencies of extreme-rainfall events, and into the potential predictability of associated natural hazards. Y1 - 2019 U6 - https://doi.org/10.1038/s41586-018-0872-x SN - 0028-0836 SN - 1476-4687 VL - 566 IS - 7744 SP - 373 EP - 377 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Riedl, Maik A1 - van Leeuwen, Peter Jan A1 - Suhrbier, Alexander A1 - Malberg, Hagen A1 - Groenemeyer, Dietrich A1 - Kurths, Jürgen A1 - Wessel, Niels T1 - Testing foetal-maternal heart rate synchronization via model-based analyses N2 - The investigation of foetal reaction to internal and external conditions and stimuli is an important tool in the characterization of the developing neural integration of the foetus. An interesting example of this is the study of the interrelationship between the foetal and the maternal heart rate. Recent studies have shown a certain likelihood of occasional heart rate synchronization between mother and foetus. In the case of respiratory-induced heart rate changes, the comparison with maternal surrogates suggests that the evidence for detected synchronization is largely statistical and does not result from physiological interaction. Rather, they simply reflect a stochastic, temporary stability of two independent oscillators with time-variant frequencies. We reanalysed three datasets from that study for a more local consideration. Epochs of assumed synchronization associated with short-term regulation of the foetal heart rate were selected and compared with synchronization resulting from white noise instead of the foetal signal. Using data-driven modelling analysis, it was possible to identify the consistent influence of the heartbeat duration of maternal beats preceding the foetal beats during epochs of synchronization. These maternal beats occurred approximately one maternal respiratory cycle prior to the affected foetal beat. A similar effect could not be found in the epochs without synchronization. Simulations based on the fitted models led to a higher likelihood of synchronization in the data segments with assumed foetal-maternal interaction than in the segment without such assumed interaction. We conclude that the data-driven model-based analysis can be a useful tool for the identification of synchronization. Y1 - 2009 UR - http://rsta.royalsocietypublishing.org/ U6 - https://doi.org/10.1098/rsta.2008.0277 SN - 1364-503X ER - TY - JOUR A1 - Ivanchenko, Mikhail V. A1 - Osipov, Grigory V. A1 - Shalfeev, V. D. A1 - Kurths, Jürgen T1 - Phase synchronization in ensembles of bursting oscillators N2 - We study the effects of mutual and external chaotic phase synchronization in ensembles of bursting oscillators. These oscillators (used for modeling neuronal dynamics) are essentially multiple time scale systems. We show that a transition to mutual phase synchronization takes place on the bursting time scale of globally coupled oscillators, while on the spiking time scale, they behave asynchronously. We also demonstrate the effect of the onset of external chaotic phase synchronization of the bursting behavior in the studied ensemble by a periodic driving applied to one arbitrarily taken neuron. We also propose an explanation of the mechanism behind this effect. We infer that the demonstrated phenomenon can be used efficiently for controlling bursting activity in neural ensembles Y1 - 2004 SN - 0031-9007 ER - TY - JOUR A1 - Ivanchenko, Mikhail V. A1 - Osipov, Grigory V. A1 - Shalfeev, V. D. A1 - Kurths, Jürgen T1 - Phase synchronization of chaotic intermittent oscillations N2 - We study phase synchronization effects of chaotic oscillators with a type-I intermittency behavior. The external and mutual locking of the average length of the laminar stage for coupled discrete and continuous in time systems is shown and the mechanism of this synchronization is explained. We demonstrate that this phenomenon can be described by using results of the parametric resonance theory and that this correspondence enables one to predict and derive all zones of synchronization Y1 - 2004 SN - 0031-9007 ER - TY - JOUR A1 - Osipov, Grigory V. A1 - Pikovskij, Arkadij A1 - Kurths, Jürgen T1 - Phase Synchronization of Chaotic Rotators N2 - We demonstrate the existence of phase synchronization of two chaotic rotators. Contrary to phase synchronization of chaotic oscillators, here the Lyapunov exponents corresponding to both phases remain positive even in the synchronous regime. Such frequency locked dynamics with different ratios of frequencies are studied for driven continuous-time rotators and for discrete circle maps. We show that this transition to phase synchronization occurs via a crisis transition to a band-structured attractor. Y1 - 2002 ER - TY - JOUR A1 - Rosenblum, Michael A1 - Pikovskij, Arkadij A1 - Kurths, Jürgen A1 - Osipov, Grigory V. A1 - Kiss, Istvan Z. A1 - Hudson, J. L. T1 - Locking-based frequency measurement and synchronization of chaotic oscillators with complex dynamics Y1 - 2002 ER - TY - JOUR A1 - Zaks, Michael A. A1 - Rosenblum, Michael A1 - Pikovskij, Arkadij A1 - Osipov, Grigory V. A1 - Kurths, Jürgen T1 - Phase synchronization of chaotic oscillations in terms of periodic orbits Y1 - 1997 SN - 1054-1500 ER - TY - JOUR A1 - Pikovskij, Arkadij A1 - Rosenblum, Michael A1 - Osipov, Grigory V. A1 - Kurths, Jürgen T1 - Phase synchronization effects in a lattice of nonidentical Rössler oscillators Y1 - 1997 ER - TY - JOUR A1 - Rosenblum, Michael A1 - Osipov, Grigory V. A1 - Pikovskij, Arkadij A1 - Kurths, Jürgen T1 - Phase synchronization of chaotic oscillators by external driving Y1 - 1997 ER - TY - JOUR A1 - Boccaletti, Stefano A1 - Kurths, Jürgen A1 - Osipov, Grigory V. T1 - The synchronization of chaotic systems Y1 - 2002 ER - TY - JOUR A1 - Osipov, Grigory V. A1 - Kurths, Jürgen T1 - Regular and chaotic phase synchronization of coupled circle maps Y1 - 2002 ER - TY - JOUR A1 - Osipov, Grigory V. A1 - Rosenblum, Michael A1 - Pikovskij, Arkadij A1 - Zaks, Michael A. A1 - Kurths, Jürgen T1 - Attractor-repeller collision and eyelet intermittency at the transition to phase synchronization N2 - The chaotically driven circle map is considered as the simplest model ofphase synchronization of a chaotic continuous-time oscillator by external periodic force. The phase dynamics is analyzed via phase-locking regions of the periodic cycles embedded in the strange attractor. It is shown that full synchronization, where all the periodic cycles are phase locked, disappears via the attractor-repeller collision. Beyond the transition an intermittent regime with exponentially rare phase slips, resulting from the trajectory's hits on an eyelet, is observed. Y1 - 1997 ER - TY - JOUR A1 - Ivanchenko, Mikhail V. A1 - Osipov, Grigory V. A1 - Shalfeev, V. D. A1 - Kurths, Jürgen T1 - Synchronization of two non-scalar-coupled limit-cycle oscillators N2 - Being one of the fundamental phenomena in nonlinear science, synchronization of oscillations has permanently remained an object of intensive research. Development of many asymptotic methods and numerical simulations has allowed an understanding and explanation of various phenomena of self-synchronization. But even in the classical case of coupled van der Pol oscillators a full description of all possible dynamical regimes, their mutual transitions and characteristics is still lacking. We present here a study of the phenomenon of mutual synchronization for two non-scalar- coupled non-identical limit-cycle oscillators and analyze phase, frequency and amplitude characteristics of synchronization regimes. A series of bifurcation diagrams that we obtain exhibit various regions of qualitatively different behavior. Among them we find mono-, bi- and multistability regions, beating and "oscillation death" ones; also a region, where one of the oscillators dominates the other one is observed. The frequency characteristics that we obtain reveal three qualitatively different types of synchronization: (i) on the mean frequency (the in-phase synchronization), (ii) with a shift from the mean frequency caused by a conservative coupling term (the anti-phase synchronization), and (iii) on the frequency of one of the oscillators (when one oscillator dominates the other). (C) 2003 Elsevier B.V. All rights reserved Y1 - 2004 ER - TY - JOUR A1 - Belykh, Vladimir N. A1 - Osipov, Grigory V. A1 - Kuckländer, Nina A1 - Blasius, Bernd A1 - Kurths, Jürgen T1 - Automatic control of phase synchronization in coupled complex oscillators N2 - We present an automatic control method for phase locking of regular and chaotic non-identical oscillations, when all subsystems interact via feedback. This method is based on the well known principle of feedback control which takes place in nature and is successfully used in engineering. In contrast to unidirectional and bidirectional coupling, the approach presented here supposes the existence of a special controller, which allows to change the parameters of the controlled systems. First we discuss general principles of automatic phase synchronization (PS) for arbitrary coupled systems with a controller whose input is given by a special quadratic form of coordinates of the individual systems and its output is a result of the application of a linear differential operator. We demonstrate the effectiveness of our approach for controlled PS on several examples: (i) two coupled regular oscillators, (ii) coupled regular and chaotic oscillators, (iii) two coupled chaotic R"ossler oscillators, (iv) two coupled foodweb models, (v) coupled chaotic R"ossler and Lorenz oscillators, (vi) ensembles of locally coupled regular oscillators, (vii) ensembles of locally coupled chaotic oscillators, and (viii) ensembles of globally coupled chaotic oscillators. Y1 - 2005 UR - http://www.agnld.uni-potsdam.de/~bernd/papers/physica_D.pdf ER -